Epoxy Resin Composition and Electronic Component Device

ABSTRACT

An epoxy resin composition includes: (A) an epoxy resin containing a compound represented by the following Formula (I); (B) a phenol resin containing a compound represented by the following Formula (II); and (C) a dihydroxynaphthalene compound containing a compound represented by the following Formula (III). In Formula (I), R represents a hydrogen atom, and n represents an integer from 0 to 10. In Formula (II), R 1  represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, or an alkoxy group having 1 or 2 carbon atoms, and each R 1  may be the same as or different from another R 1 . n represents an integer from 0 to 10. In Formula (III), R 1  represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, or an alkoxy group having 1 or 2 carbon atoms.

TECHNICAL FIELD

The present invention relates to an epoxy resin composition and anelectronic component device.

BACKGROUND ART

Hitherto, curable resins such as epoxy resins are widely used in fieldssuch as molding materials, materials for laminates and adhesives,various kinds of electronic and electrical components, and coating andink materials. In particular, cured products of epoxy resins are widelyused as sealing materials in the field related to the sealing techniqueof electronic component elements such as a transistor and an IC. Thereason for that is because that cured products of epoxy resins arebalanced in properties such as moldability, electrical properties,moisture resistance, heat resistance, mechanical properties, andadhesion with insert products.

Meanwhile, in recent years, increase in speed and density has beenadvanced in the electronic component field, and thus heat generationfrom electronic components has been remarkable. Electronic componentsoperated under a high temperature environment, for example in-vehicleapplications, have been increased in number. Hence, a requirement ofimprovement in reliability related to a use under a high temperatureenvironment, for example changes in physical properties being small indegree even in a use under a high temperature environment compared to ause under room temperature, has been increased to the plastics,particularly cured products of epoxy resins, which are used forelectronic components.

Here, as a method of improving reliability under a high temperatureenvironment, there is a method, in which glass transition temperature iselevated. As the method of elevating glass transition temperature, amethod using a trisphenolmethane type epoxy resin together with a phenolnovolac, and the like has been reported (for example, see Complete Workson sealing techniques and material development in the latestsemiconductor and LED (TECHNICAL INFORMATION INSTITUTE CO., LTD), pp.22-24 (2006)). According to this method, it is regarded that the glasstransition temperature of a cured product of an epoxy resin can beelevated to about 200° C. or so and thus high heat resistance can beimparted. In addition, a method using a polyfunctional epoxy resin suchas a trisphenolmethane type epoxy resin together with a polyfunctionalphenol resin such as a trisphenolmethane type phenol resin is also knownas a method elevating a glass transition temperature to about 200° C. orso.

In addition, a composition containing a dihydroxynaphthalene aralkylphenol resin is suggested as an epoxy resin composition for sealing, ofwhich the curvature is small in a BGA package, the temperature change ofthe curvature at from room temperature (25° C.) to the reflowtemperature is small in degree, the defects at the time of secondmounting are few, and the fluidity is favorable, in which the occurrenceof defects such as a void and a gold wire flow is not frequent, andreliability such as moldability, moisture resistance, and hightemperature exposure property does not decrease, which is non-halogenand non-antimony, and of which the flame retardance is favorable (forexample, see Japanese Patent Application Laid-Open (JP-A) No.2009-221357).

SUMMARY OF INVENTION Technical Problem

However, the present inventors conducted investigations, and as aresult, the following fact is demonstrated. A cured product of acomposition containing a trisphenolmethane type epoxy resin of therelated art exhibits a high glass transition temperature, but theelastic modulus thereof is significantly decreased at near 200° C. Henceit cannot be said that the reliability thereof under a high temperatureenvironment of, for example, 200° C. is sufficient. In the market, anepoxy resin composition excellent in reliability that the change inphysical properties of a cured product is small in degree even in a useunder a high temperature environment is strongly desired.

Therefore, an object of the present invention is to provide an epoxyresin composition that exhibits a high glass transition temperature whenformed as a cured product, and that exhibits a minor change in elasticmodulus and a minor decrease in mass even when used in a hightemperature environment, and an electronic component device providedwith an element sealed by the epoxy resin composition.

Means for Solving Problems

The inventors have conducted intensive investigations in order to solvethe problems described above, and as a result, have found out that acured product of an epoxy resin composition containing a particularepoxy resin and a particular phenol resin exhibits a high glasstransition temperature, a little change in elastic modulus and a littledecrease in mass even in a use under a high temperature environment, andan excellent reliability under a high temperature environment, therebyreaching to complete the present invention. Specifically, the presentinvention relates to the following aspects.

<1> An epoxy resin composition, including: (A) an epoxy resin containinga compound represented by the following Formula (I); (B) a phenol resincontaining a compound represented by the following Formula (II); and (C)a dihydroxynaphthalene compound containing a compound represented by thefollowing Formula (III).

In Formula (I), R represents a hydrogen atom, and n represents aninteger from 0 to 10.

In Formula (II), R¹ represents a hydrogen atom, an alkyl group havingfrom 1 to 6 carbon atoms, or an alkoxy group having 1 or 2 carbon atoms,and each R¹ may be the same as or different from another R¹. nrepresents an integer from 0 to 10.

In Formula (III), R¹ represents a hydrogen atom, an alkyl group havingfrom 1 to 6 carbon atoms, or an alkoxy group having 1 or 2 carbonatoms.)

<2> The epoxy resin composition according to <1>, in which the compoundrepresented by Formula (II) contains a phenol resin represented by thefollowing Formula (IV).

In Formula (IV), R¹ represents a hydrogen atom, and n represents aninteger from 0 to 10.

<3> The epoxy resin composition according to <1> or <2>, in which acontent of a total amount of the compound represented by Formula (III)with respect to a total amount of the compound represented by Formula(II) and the compound represented by Formula (III) is from 10% by massto 55% by mass.

<4> The epoxy resin composition according to any one of <1> to <3>,further containing an antioxidant.

<5> An electronic component device, containing an element sealed by theepoxy resin composition according to any one of <1> to <4>.

Advantageous Effects of Invention

According to the present invention, it is possible to provide an epoxyresin composition that exhibits a high glass transition temperature whenformed as a cured product, and that exhibits a minor change in elasticmodulus and a minor decrease in mass even when used in a hightemperature environment, and an electronic component device excellent inreliability under a high temperature environment.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a GPC chart for phenol resin 1.

FIG. 2 is a GPC chart for phenol resin 2.

FIG. 3 is a GPC chart for phenol resin 3.

DESCRIPTION OF EMBODIMENTS

Hereinafter, the present invention will be described in detail.

Meanwhile, “to” in the specification denotes the range including thenumerical values written before and after “to” as the minimum value andthe maximum value, respectively. In addition, the amount of each ofconstituents in a composition in the specification means the totalamount of the plural materials present in the composition unlessotherwise stated in a case in which more than one material correspondingto each of the constituents are present in the composition.

<Epoxy Resin Composition>

The epoxy resin composition of the present invention is an epoxy resincomposition containing (A) an epoxy resin containing a compoundrepresented by the following Formula (I), (B) a phenol resin containinga compound represented by the following Formula (II), and (C) adihydroxynaphthalene compound containing a compound represented by thefollowing Formula (III). The epoxy resin composition of the presentinvention is solid at room temperature (25° C.).

Hereinafter, each of the constituents constituting the epoxy resincomposition of the present invention will be described.

[(A) Epoxy Resin]

The epoxy resin composition used in the present invention contains acompound represented by the following Formula (I) (hereinafter, it willbe referred to as a trisphenolmethane type epoxy resin.).

In Formula (I), R represents a hydrogen atom. n represents an integerfrom 0 to 10.

It is possible to improve particularly heat resistance in a case inwhich the epoxy resin composition contains the trisphenolmethane typeepoxy resin. Since the trisphenolmethane type epoxy resin has a highcontent of aromatic ring in the resin structure and is polyfunctional, acured product thereof exhibits a high glass transition temperature, andalso, it is considered that it is possible to obtain a resin compositionexhibiting a high reliability under a high temperature environment whenformed as a cured product by combining with a phenol resin to bedescribed below.

In a case in which R's in Formula (I) are a hydrogen atom, moldabilityis excellent. As the above described compound, in which R's are ahydrogen atom, a commercial product, for example, Trade name: EPPN-500SERIES manufactured by NIPPON KAYAKU Co., Ltd. or Trade name: 1032H60manufactured by Mitsubishi Chemical Corporation is affordable.

n in Formula (I) is an integer from 0 to 10 and preferably an integerfrom 0 to 8 in terms of fluidity and moldability.

Moreover, the compound represented by Formula (I) may contain a compoundrepresented by the following Formula (I-1) used when the compoundrepresented by Formula (I) is synthesized.

In Formula (I-1), R represents a hydrogen atom.

In terms of fluidity and heat resistance, the compound represented byFormula (I-1) is preferably contained at from 5% by mass to 90% by mass,more preferably contained at from 10% by mass to 80% by mass, and stillmore preferably contained at from 20% by mass to 70% by mass withrespect to the total mass of the compound represented by Formula (I) andthe compound represented by Formula (I-1).

An epoxy equivalent of the trisphenolmethane type epoxy resinrepresented by Formula (I), which includes the compound represented byFormula (I-1), is preferably from 100 to 220, more preferably from 120to 200, and still more preferably from 140 to 185.

As a method of measuring the epoxy equivalent, a general method can beadopted. For example, the epoxy equivalent can be measured by a methodbased on JIS K7236.

In addition, another epoxy resin can be used together in the presentinvention in the range of not impairing the effect obtained using thetrisphenolmethane type epoxy resin. The epoxy resin usable together withthe trisphenolmethane type epoxy resin is not particularly limited aslong as a compound has two or more epoxy groups in one molecule.

Examples of the epoxy resin usable together with the trisphenolmethanetype epoxy resin include a bisphenol A type epoxy resin, a bisphenol Ftype epoxy resin, a bisphenol S type epoxy resin, a naphthalene typeepoxy resin, a phenol novolac type epoxy resin, a cresol novolac typeepoxy resin, a dihydroxybenzene novolac type epoxy resin, a phenolaralkyl type epoxy resin, a biphenyl type epoxy resin, adicyclopentadiene type epoxy resin, a glycidyl ester type epoxy resin, aglycidylamine type epoxy resin, a hydantoin type epoxy resin, and anisocyanurate type epoxy resin. These epoxy resins may be used singly orin combination of two or more kinds thereof with respect to thetrisphenolmethane type epoxy resin.

As a content in a case in which another epoxy resin is used together,the trisphenolmethane type epoxy resin is preferably 50% by mass ormore, and more preferably 80% by mass or more in the total amount ofepoxy resin. Excellent heat resistance can be obtained by setting thecontent of the trisphenolmethane type epoxy resin within the rangedescribed above.

[(B) Phenol Resin]

The epoxy resin composition used in the present invention contains acompound represented by the following Formula (II), hereinafter, it willbe referred to as a naphthalenediol aralkyl resin.

In Formula (II), R¹ represents a hydrogen atom, an alkyl group havingfrom 1 to 6 carbon atoms, or an alkoxy group having 1 or 2 carbon atoms,and each R¹ may be the same as or different from another R¹. nrepresents an integer from 0 to 10.

Heat resistance particularly at a high temperature can be improved usingthe trisphenolmethane type epoxy resin together with the naphthalenediolaralkyl resin. The reason for this is considered as that thenaphthalenediol aralkyl resin has a rigid structure of a naphthalenering in the resin structure and is polyfunctional, and thus the glasstransition temperature of a cured product is high. Moreover, it isconsidered that the restrictiveness of the molecular chain of the epoxyresin after curing reaction can be increased by two hydroxyl groupsbonded to the naphthalene ring, and thus a resin composition having highreliability under a high temperature environment when formed as a curedproduct can be obtained by the combination with the epoxy resindescribed above.

In detail, since the trisphenolmethane type epoxy resin has a highcontent of aromatic ring and is polyfunctional, crosslink density can beincreased by the reaction with a hydroxyl group of the naphthalenediolaralkyl resin. Moreover, the trisphenolmethane type epoxy resin can bestacked in a cured product by two hydroxyl groups bonded to anaphthalene ring of the naphthalenediol aralkyl resin, and further astacking can be formed by the naphthalene ring of the naphthalenediolaralkyl resin. It is considered that the restrictiveness of themolecular chain can be effectively increased by these actions, andelastic modulus retention at a high temperature can be increased.

R¹s in Formula (II) represent a hydrogen atom, an alkyl group havingfrom 1 to 6 carbon atoms, or an alkoxy group having 1 or 2 carbon atoms,and is preferably a hydrogen atom in terms of the property of elasticmodulus retention.

n in Formula (II) is preferably an integer from 0 to 10, and morepreferably an integer from 0 to 8 in terms of fluidity, moldability, andflame retardance.

In addition, a hydroxyl group in Formula (II) is preferably bonded tothe 1-position and 6-position of a naphthalene structure in terms ofachieving the effect of the present invention. Accordingly, the compoundrepresented by Formula (II) is preferably a compound represented by thefollowing Formula (IV).

In Formula (IV), R¹ represents a hydrogen atom. n represents an integerfrom 0 to 10, and the preferred range is the same as the preferred rangeof Formula (II).

As a 1,6-naphthalenediol aralkyl resin represented by Formula (IV),SN-375, SN-395 (both of them are trade names and manufactured by NipponSteel Chemical Co., Ltd.), and the like are affordable.

In addition, another phenol resin can be used together in the presentinvention in the range of not impairing the effect obtained using thenaphthalenediol aralkyl resin. As the usable phenol resin, a phenolresin generally used for an epoxy resin composition for sealing isexemplified, and there is no particular limitation.

Examples of the usable phenol resin include a novolac type phenol resinobtained by condensation or cocondensation of phenols such as phenol,cresol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, oraminophenol, and/or naphthols such as α-naphthol, β-naphthol, ordihydroxynaphthalene, and a compound having an aldehyde group such asformaldehyde, benzaldehyde, or salicylaldehyde in the presence of anacid catalyst; an aralkyl type phenol resin such as a phenol aralkylresin, a biphenylene type phenol aralkyl resin, or a naphthol aralkylresin synthesized from phenols and/or naphthols and dimethoxy-p-xyleneor bis(methoxymethyl) biphenyl; a dicyclopentadiene type phenol resinsuch as a dicyclopentadiene type phenol novolac resin or adicyclopentadiene type naphthol novolac resin synthesized from phenolsand/or naphthols and dicyclopentadiene by copolymerization; atriphenylmethane type phenol resin; a terpene-modified phenol resin; apara-xylylene and/or meta-xylylene-modified phenol resin; amelamine-modified phenol resin; a cyclopentadiene-modified phenol resin;and a phenol resin obtained by copolymerization of two or more kindsthereof.

These phenol resins may be used singly or in combination of two or morekinds thereof with respect to the naphthalenediol aralkyl resin. As thecontent in a case in which another phenol resin is used together, thenaphthalenediol aralkyl resin is preferably 50% by mass or more, andmore preferably 80% by mass or more in total phenol resins in order tosufficiently obtain the effect of the naphthalenediol aralkyl resin.

The total amount of the (B) phenol resin containing a naphthalenediolaralkyl resin is preferably added with respect to the total amount ofthe (A) epoxy resin containing a trisphenolmethane type epoxy resin suchthat the hydroxyl group of the (B) phenol resin and the epoxy group ofthe (A) epoxy resin become nearly the same equivalent.

Specifically, the ratio (the number of hydroxyl group in a curingagent/the number of epoxy group in an epoxy resin) of the number ofhydroxyl group in the (B) phenol resin (curing agent) to the number ofepoxy group in the (A) epoxy resin is not particularly limited, and ispreferably set to the range of from 0.5 to 2, and more preferably set tothe range of from 0.6 to 1.3 in order to suppress the unreacted portionof the respective functional groups to a small amount. The ratio isstill more preferably set to the range of from 0.8 to 1.2 in order toobtain an epoxy resin composition for sealing, which is excellent inmoldability.

[(C) Dihydroxynaphthalene Compound]

The epoxy resin compound of the present invention contains a compoundrepresented by the following Formula (III), hereinafter, it is referredto as a dihydroxynaphthalene compound.

In Formula (III), R¹ represents a hydrogen atom, an alkyl group havingfrom 1 to 6 carbon atoms, or an alkoxy group having 1 or 2 carbon atoms.

The dihydroxynaphthalene compound is a compound used as a raw materialwhen the naphthalenediol aralkyl resin is synthesized. Fluidity of theepoxy resin composition can be improved by containing thedihydroxynaphthalene compound in the epoxy resin composition, andfluidity and heat resistance can be adjusted by adjusting the blendingratio with the naphthalenediol aralkyl resin. Meanwhile, thedihydroxynaphthalene compound has a rigid structure of a naphthalenering and two hydroxyl groups bonded to the naphthalene ring in the samemanner as a naphthalenediol aralkyl resin. For that reason, it isconsidered that the heat resistance of the resin composition can bemaintained while improving the fluidity compared to other low molecularweight phenol compounds and the like.

Specific examples of the dihydroxynaphthalene compound include1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene,1,7-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, and2,7-dihydroxynaphthalene. In particular, 1,6-dihydroxynaphthalene ispreferably used in terms of fluidity as a resin composition.

The content ratio of the naphthalenediol aralkyl resin to thedihydroxynaphthalene compound is as follows. The content of thedihydroxynaphthalene compound is preferably from 10% by mass to 55% bymass, and more preferably from 20% by mass to 50% by mass with respectto the total amount of the naphthalenediol aralkyl resin and thedihydroxynaphthalene compound in terms of fluidity and heat resistance.Fluidity is improved by setting the content of the dihydroxynaphthalenecompound to 10% by mass or more, and excellent heat resistance (high Tg)is easily obtained by setting the content to 55% by mass or less.

Here, the content of the dihydroxynaphthalene compound with respect tothe total amount of the naphthalenediol aralkyl resin and thedihydroxynaphthalene compound can be calculated from the area integralratio of GPC detected by a refractive index detector (RI).

The hydroxyl group equivalent when the naphthalenediol aralkyl resinrepresented by Formula (II) and the dihydroxynaphthalene compoundrepresented by Formula (III) are summed is preferably from 70 to 140,more preferably from 80 to 135, and still more preferably from 90 to130.

As a method of measuring the hydroxyl group equivalent, a general methodcan be adopted, and for example, the hydroxyl group equivalent can bemeasured by a method based on JIS K0070.

[(D) Antioxidant]

An antioxidant is preferably contained in the epoxy resin composition ofthe present invention if necessary in order to prevent the oxidation ofresin. An antioxidant is an additive to prevent the oxidation of resin.An epoxy resin composition containing the above described epoxy resinand phenol resin is capable of reducing the decrease in elastic modulusat a high temperature, and further, the mass decrease of a cured productunder high temperature exposure can be suppressed by containing anantioxidant in the resin composition of the above described epoxy resinand phenol resin.

Examples of the antioxidant include a phenolic antioxidant, aphosphite-based antioxidant, a sulfur-based antioxidant, and a hinderedamine-based antioxidant. These antioxidants can be used together. Inparticular, a phenolic antioxidant is preferably contained. Thethermo-oxidative degradation of resin can be effectively prevented byusing a phenolic antioxidant. The thermo-oxidative degradation of resincan be further effectively suppressed by containing a phenolicantioxidant and further using other antioxidants such as aphosphite-based antioxidant, a sulfur-based antioxidant, and a hinderedamine-based antioxidant together if necessary.

Examples of the phenolic antioxidant include1,3,5-tris(3′,5′-di-t-butyl-4′-hydroxybenzyl) isocyanurate,1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane,3-(4′-hydroxy-3′,5′-di-t-butylphenyl) propionate-n-octadecyl,3-(4′-hydroxy-3′,5′-di-t-butylphenyl) propionate-n-octadecyl,3,9-bis-{2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl}2,4,8,10-tetraoxaspiro[5.5]undecane,2-t-butyl-4-methoxyphenol, 3-t-butyl-4-methoxyphenol,2,6-di-t-butyl-4-ethylphenol,2,2′-methylene-bis(4-methyl-6-t-butylphenol),4,4′-thiobis-(3-methyl-6-t-butylphenol),4,4′-butylidene-bis(3-methyl-6-t-butylphenol),1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, andtetrakis-[methylene-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate]methane.

The phenolic antioxidant is preferably a phenolic antioxidant, in whicheach of two carbon atoms adjacent to a carbon atom bonded to a phenolichydroxyl group has an organic group having one or more carbon atoms.Specific examples of the organic group preferably include methyl group,ethyl group, propyl group, butyl group, isopropyl group, and t-butylgroup. More preferably, the phenolic antioxidant is preferably aphenolic antioxidant, in which each of two carbon atoms adjacent to acarbon atom bonded to a phenolic hydroxyl group has an organic groupcontaining a tertiary carbon as a substituent. As the organic groupcontaining a tertiary carbon, t-butyl group is specifically exemplified.

The phenolic antioxidant may be synthesized and/or prepared according toa common method, or a commercially available product may be purchased.Examples of the commercially available product of antioxidant include“YOSHINOX BB”, “YOSHINOX BHT”, and “YOSHINOX 425” (these are trade namesand manufactured by API CORPORATION), “TTIC” and “TTAD” (these are tradenames and manufactured by TORAY INDUSTRIES, INC.), “IRGANOX L107” (thisis a trade name and manufactured by BASF Japan Ltd.), and “AO-20”,“AO-30”, “AO-40”, “AO-50”, “AO-50F”, “AO-60”, “AO-60G”, “AO-70”,“AO-80”, and “AO-330” (these are trade names and manufactured by ADEKACORPORATION). These may be used singly or in combination of two or morekinds thereof.

Among them, a compound represented by the following Formula (V)containing four structures, each structure having a t-butyl group ateach ortho position on both sides of a phenolic hydroxyl group, ispreferable. The effect of reliability improvement is more expected froma compound, in which a phenolic hydroxyl group is surrounded by a morebulky substituent and thus the steric hindrance thereof is high, andwhich contains such a structure more in number. As such a compound,“AO-60”, which is a trade name and manufactured by ADEKA CORPORATION, isexemplified.

The content of the phenolic antioxidant in the epoxy resin compositionof the present invention is not particularly limited as long as theinhibitory effect of mass decrease is achieved. However, since a glasstransition temperature decreases in some cases if a large amount ofantioxidant is blended, the antioxidant is preferably blended in totalfrom 0.1 part by mass to 20 parts by mass, and more preferably blendedin total from 1 part by mass to 10 parts by mass with respect to 100parts by mass of the total epoxy resin in terms of glass transitiontemperature (heat resistance) of the epoxy resin composition. Theinhibitory effect of mass decrease of a cured product is sufficientlyachieved by setting the content of the phenolic antioxidant to 0.1 partby mass or more. In addition, the decrease in glass transitiontemperature (heat resistance) of a cured product is suppressed bysetting the content of the phenolic antioxidant to 20 parts by mass orless.

Examples of the phosphite-based antioxidant include triphenyl phosphite,diphenylisodecyl phosphite, phenyldiisodecyl phosphite,4,4′-butylidene-bis(3-methyl-6-t-butyl-phenylditridecyl)phosphite,cyclic neopentanetetrayl bis(nonylphenyl)phosphite, cyclicneopentanetetrayl bis(dinonylphenyl)phosphite, cyclic neopentanetetrayltris(nonylphenyl)phosphite, cyclic neopentanetetrayltris(dinonylphenyl)phosphite,10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide,2,2-methylene-bis(4,6-di-t-butylphenyl) octyl phosphite, diisodecylpentaerythritol, and tris(2,4-di-t-butylphenyl)phosphite. These may beused singly or in combination of two or more kinds thereof.

Examples of the sulfur-based antioxidant includetetrakis[methylene-3-(dodecylthio) propionate]methane, dilauryl3,3′-thiodipropionate, distearyl 3,3′-thiodipropionate, N-cyclohexylthiophthalimide, and N-n-butyl benzene sulfonamide. These may be usedsingly or in combination of two or more kinds thereof.

Examples of the hindered amine-based antioxidant includebis(2,2,6,6-tetramethyl-4-piperidyl) sebacate,bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate,3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl) pyrrolidine-2,5-dione,N-methyl-3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidine-2,5-dione,N-acetyl-3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidine-2,5-dione,poly[{6-(1,1,3,3-tetramethylbutyl)imino-1,3,5-triazine-2,4-diyne}{(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}]. These may be used singly orin combination of two or more kinds thereof.

In addition, the above described antioxidants may be melted and blendedwith the epoxy resin and/or the phenol resin in advance, and then used.The antioxidant can be sufficiently dispersed in the resin compositionby melting and blending the antioxidant with the epoxy resin and/or thephenol resin in advance.

[(E) Curing Accelerator]

The molding material of the present invention preferably contains (E) acuring accelerator in order to promote the curing reaction. As the (E)curing accelerator used in the present invention, a curing acceleratorgenerally used for an epoxy resin molding material for sealing isexemplified, and there is no particular limitation.

Examples of the curing accelerator include a cycloamidine compound suchas 1,8-diazabicyclo[5.4.0]undecene-7,1,5-diazabicyclo[4.3.0]nonene-5,and 5,6-dibutylamino-1,8-diazabicyclo[5.4.0]undecene-7, and a compoundhaving intramolecular polarization, which is obtained by adding maleicanhydride, a quinone compound such as 1,4-benzoquinone, 2,5-toluquinone,1,4-naphthoquinone, 2,3-dimethyl benzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone,2,3-dimethoxy-1,4-benzoquinone, and phenyl-1,4-benzoquinone, and acompound having a π-bond such as diazophenylmethane and a phenol resinto these cycloamidine compounds; tertiary amines such asbenzyldimethylamine, triethanolamine, dimethylaminoethanol, andtris(dimethylaminomethyl)phenol, and derivatives thereof; imidazolessuch as 2-methylimidazole, 2-phenylimidazole,2-phenyl-4-methylimidazole, and 2-heptadecylimidazole, and derivativesthereof; an organic phosphine such as tributylphosphine,methyldiphenylphosphine, triphenylphosphine,tris(4-methylphenyl)phosphine, tris(4-butylphenyl)phosphine,diphenylphosphine, and phenylphosphine, and a phosphorus compound havingintramolecular polarization, which is obtained by adding maleicanhydride, the above described quinone compound, and a compound having aπ-bond such as diazophenylmethane and a phenol resin to thesephosphines; and a tetraphenylborate such as tetraphenylphosphoniumtetraphenylborate, triphenylphosphine tetraphenylborate,2-ethyl-4-methylimidazole tetraphenylborate, and N-methylmorpholinetetraphenylborate, and a derivative thereof. These may be used singly orin combination of two or more kinds thereof.

Among them, an adduct of a tertiary phosphine and a quinone compound ispreferable, and an adduct of triphenylphosphine and benzoquinone is morepreferable in terms of curing property and fluidity. An adduct of acycloamidine compound and a phenol resin is preferable, and a novolactype phenol resin salt of diazabicycloundecene is more preferable interms of storage stability.

The total blending amount of the adduct of a tertiary phosphine and aquinone and/or the adduct of a cycloamidine compound and a phenol resinas a curing accelerator is preferably 60% by mass or more, and morepreferably 80% by mass or more in the total amount of curingaccelerator.

The tertiary phosphine used for the adduct of a tertiary phosphine and aquinone compound is not particularly limited, and examples thereofinclude tributylphosphine and a tertiary phosphine having an aryl group,such as dibutylphenylphosphine, butyldiphenylphosphine,ethyldiphenylphosphine, triphenylphosphine,tris(4-methylphenyl)phosphine, tris(4-ethylphenyl)phosphine,tris(4-propylphenyl)phosphine, tris(4-butylphenyl)phosphine,tris(isopropylphenyl)phosphine, tris(t-butylphenyl)phosphine,tris(2,4-dimethylphenyl)phosphine, tris(2,6-dimethylphenyl)phosphine,tris(2,4,6-trimethylphenyl)phosphine,tris(2,6-dimethyl-4-ethoxyphenyl)phosphine,tris(4-methoxyphenyl)phosphine, and tris(4-ethoxyphenyl)phosphine.Triphenylphosphine is preferable in terms of moldability.

In addition, the quinone compound used for the adduct of a tertiaryphosphine and a quinone compound is not particularly limited, andexamples thereof include o-benzoquinone, p-benzoquinone, diphenoquinone,1,4-naphthoquinone, and anthraquinone. p-benzoquinone is preferable interms of moisture resistance or storage stability.

Specific examples of the curing accelerator include a cycloamidinecompound, which is a diazabicycloalkene, such as1,5-diazabicyclo[4.3.0]non-5-ene, and 1,8-diazabicyclo[5.4.0]undec-7-en;a derivative of cycloamidine compound such as a phenol novolac salt ofcycloamidine compound; a compound having intramolecular polarization,which is obtained by adding maleic anhydride, a quinone compound such as1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethyl benzoquinone,2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone,and phenyl-1,4-benzoquinone, and a compound having a π-bond such asdiazophenylmethane and a phenol resin to a cycloamidine compound or aderivative thereof; a tertiary amine compound such asbenzyldimethylamine, triethanolamine, dimethylaminoethanol, andtris(dimethylaminomethyl)phenol, and a derivative thereof; a imidazolecompound such as 2-methylimidazole, 2-phenylimidazole, and2-phenyl-4-methylimidazole, and a derivative thereof; an organicphosphine compound such as tributylphosphine, methyldiphenylphosphine,triphenylphosphine, tris(4-methylphenyl)phosphine,tris(4-butylphenyl)phosphine, diphenylphosphine, and phenylphosphine,and a phosphorus compound having intramolecular polarization, which isobtained by adding maleic anhydride, the above described quinonecompound, and a compound having a π-bond such as diazophenylmethane anda phenol resin to these organic phosphine compounds; and atetraphenylborate such as tetraphenylphosphonium tetraphenylborate,triphenylphosphine tetraphenylborate, 2-ethyl-4-methylimidazoletetraphenylborate, and N-methylmorpholine tetraphenylborate, and aderivative thereof.

These compounds may be used singly or in combination of two or morekinds thereof. Among them, an adduct of an organic phosphine and aquinone compound is suitable in terms of fluidity and moistureresistance.

The content of the (E) curing accelerator in the epoxy resin compositionaccording to the present invention is not particularly limited as longas the effect of curing acceleration is achieved. The (E) curingaccelerator is preferably blended in total at the proportion of from 0.1part by mass to 10 parts by mass, and more preferably blended in totalat the proportion of from 1 part by mass to 7 parts by mass with respectto 100 parts by mass of the total (A) epoxy resin in terms ofimprovement in fluidity and curing property at the time of moistureabsorption of the resin composition. The curing of resin compositioneasily proceeds in a short time by setting the content of the (E) curingaccelerator to 0.1 part by mass or more, and an appropriate curing speedis obtained and thus a favorable molded product is easily obtained bysetting the content of the (E) curing accelerator to 10 parts by mass orless.

[(F) Inorganic Filler]

An inorganic filler is preferably contained in the epoxy resincomposition of the present invention if necessary. The inorganic fillermay be blended for the purpose of improving the linear expansioncoefficient, thermal conductivity, elastic modulus, or the like of acured product of epoxy resin composition. Specific examples of theinorganic filler include a fine powder such as fused silica, crystallinesilica, glass, alumina, calcium carbonate, zirconium silicate, calciumsilicate, silicon nitride, aluminum nitride, boron nitride, beryllia,zirconia, zircon, forsterite, steatite, spinel, mullite, titania, talc,clay, and mica, and a spheroidized bead thereof.

Examples of the inorganic filler exhibiting flame retardant effectinclude aluminum hydroxide, magnesium hydroxide, a composite metalhydroxide such as a composite hydroxide of magnesium and zinc, zincborate, and zinc molybdate.

Among these inorganic fillers, fused silica is preferable in terms ofthe reduction in linear expansion coefficient, and alumina is preferablein terms of high thermal conductivity. These inorganic fillers may beused singly or in combination of two or more kinds thereof.

The content of the inorganic filler is not particularly limited as longas the effect of the present invention is obtained, and is preferably50% by mass or more, more preferably from 60% by mass to 95% by mass interms of flame retardance, and still more preferably from 70% by mass to90% by mass in the epoxy resin composition. The property of curedproduct, such as linear expansion coefficient, thermal conductivity, andelastic modulus is improved by setting the content of the inorganicfiller to 50% by mass or more. The increase in viscosity of the epoxyresin composition is reduced, sufficient fluidity is easily obtained,and thus moldability is improved by setting the content of the inorganicfiller to 95% by mass or less.

The average particle size (D50) of the inorganic filler is preferablyfrom 0.1 μm to 50 μm, and more preferably from 10 μm to 30 μm. Theincrease in viscosity of the epoxy resin composition is suppressed bysetting the average particle size to 0.1 μm or more, and the separationbetween the resin constituent and the inorganic filler can be reduced bysetting the average particle size to 50 μm or less. Hence, it isprevented that a cured product is ununiform, the property of curedproduct varies, and the filling property to a narrow opening decreasesby setting the average particle size within the above described range.

A volume average particle size (D50) is a particle size at which thecumulation becomes 50% by volume when a volume cumulative distributioncurve is drawn from the smaller size side in a particle sizedistribution. The measurement can be performed by dispersing a sample inpurified water containing a surfactant, and using a laser diffractionparticle size distribution measuring apparatus (for example, SALD-3000Jmanufactured by Shimadzu Corporation).

The particle shape of an inorganic filler is preferably a sphericalshape rather than a square shape, and the particle distribution of theinorganic filler is preferably distributed in a wide range, in terms offluidity. For example, in a case in which the inorganic filler isblended at 75% by volume or more with respect to the epoxy resincomposition, it is preferable that 70% by mass or more of the inorganicfiller is a spherical particle and the particle distribution of theinorganic filler is distributed in a wide range of from 0.1 μm to 80 μm.Since such a inorganic filler easily takes the closest packingstructure, the increase in viscosity of the epoxy resin composition issmall in degree even the content of the inorganic filler is increased,and thus an epoxy resin composition excellent in fluidity can beobtained.

The specific surface area of the inorganic filler is preferably from 0.1m²/g to 10 m²/g, and more preferably from 0.5 m²/g to 6.0 m²/g in termsof flame retardance and fluidity.

[Various Additives]

The epoxy resin composition of the present invention can contain variousadditives to be exemplified below, such as a coupling agent, an ionexchanger, a mold releasing agent, a stress relaxing agent, a flameretardant, and a colorant if necessary in addition to the epoxy resin,the phenol resin, the antioxidant, the curing accelerator, and theinorganic filler, which are described above. Provided that the additiveis not limited to the additives to be described below, and variousadditives well-known in the related technical field may be added to theepoxy resin composition of the present invention if necessary.

(Coupling Agent)

A well-known coupling agent such as various silane compounds such as anepoxysilane, a mercaptosilane, an aminosilane, an alkylsilane, aureidosilane, and a vinylsilane, a titanium-based compound, an aluminumchelate, and an aluminum/zirconium-based compound is preferably added tothe epoxy resin composition of the present invention if necessary inorder to increase the adhesion between the resin constituent and theinorganic filler.

The content of the coupling agent is preferably from 0.05% by mass to 5%by mass, and more preferably from 0.1% by mass to 2.5% by mass withrespect to the inorganic filler. The adhesion with a frame can beimproved by setting the content to 0.05% by mass or more, and themoldability of a package is improved by setting the content to 5% bymass or less. These coupling agents may be used singly or in combinationof two or more kinds thereof.

(Ion Exchanger)

The epoxy resin composition of the present invention preferably containsan anion exchanger if necessary. In particular, in a case in which theepoxy resin composition is used as a molding material for sealing, ananion exchanger is preferably contained in terms of improving themoisture resistance and high temperature exposure property of anelectronic component device equipped with an element to be sealed.

The anion exchanger is not particularly limited, and a conventionallyknown anion exchanger can be used. Examples of the anion exchangerinclude a hydrotalcite or a hydrous oxide of an atom selected frommagnesium, aluminum, titanium, zirconium, or bismuth. These may be usedsingly or in combination of two or more kinds thereof.

(Mold Releasing Agent)

A mold releasing agent is preferably blended to the epoxy resincomposition of the present invention in order to impart favorable moldrelease property with a mold at the time of molding. The mold releasingagent used in the present invention is not particularly limited, and aconventionally known mold releasing agent can be used.

Examples of the mold releasing agent include carnauba wax, a higherfatty acid such as montanic acid and stearic acid, a metal salt ofhigher fatty acid, an ester wax such as an ester of montanic acid, and apolyolefin wax such as an oxidized polyethylene and a non-oxidizedpolyethylene. These may be used singly or in combination of two or morekinds thereof. Among these, an oxidized type or non-oxidized typepolyolefin wax is preferable.

The content of the mold releasing agent is preferably from 0.01% by massto 10% by mass, and more preferably from 0.1% by mass to 5% by mass withrespect to the epoxy resin. The effect of mold release property iseasily obtained by setting the content of the mold releasing agent to0.01% by mass or more, and adhesion is improved by setting the contentof the mold releasing agent to 10% by mass or less.

(Stress Relaxing Agent)

A stress relaxing agent such as a silicone oil and a silicone rubberpowder is preferably blended to the epoxy resin composition of thepresent invention if necessary. The curvature deformation amount ofpackage and package crack can be reduced by blending the stress relaxingagent.

The usable stress relaxing agent is not particularly limited as long asthe stress relaxing agent is a publicly known flexing agent (stressrelaxing agent), which is generally used. Examples of the flexing agent,which is generally used, include a thermoplastic elastomer such as asilicone-based thermoplastic elastomer, a styrene-based thermoplasticelastomer, an olefin-based thermoplastic elastomer, a urethane-basedthermoplastic elastomer, a polyester-based thermoplastic elastomer, apolyether-based thermoplastic elastomer, a polyamide-based thermoplasticelastomer, and a polybutadiene-based thermoplastic elastomer; a rubberpowder such as NR (natural rubber), NBR (acrylonitrile-butadienerubber), an acrylic rubber, a urethane rubber, and a silicone powder;and a rubber powder having a core shell structure such as a methylmethacrylate-styrene-butadiene copolymer (MBS), a methylmethacrylate-silicone copolymer, and a methyl methacrylate-butylacrylate copolymer. These may be used singly or in combination of two ormore kinds of thereof.

(Flame Retardant)

A flame retardant is preferably blended to the epoxy resin compositionof the present invention if necessary in order to impart flameretardance. The flame retardant used in the present invention is notparticularly limited, and examples thereof include a well-known organicor inorganic compound containing a halogen atom, an antimony atom, anitrogen atom or a phosphorus atom, and a metal hydroxide. These may beused singly or in combination of two or more kinds thereof.

(Colorant)

A publicly known colorant such as carbon black, an organic dye, anorganic pigment, titanium oxide, red lead, and red iron oxide can beblended to the epoxy resin composition of the present invention.

<Preparation of Epoxy Resin Composition>

The epoxy resin composition of the present invention can be preparedusing any technique as long as various raw materials can be uniformlydispersed and mixed. As a general preparation method, a method, in whicha raw material of a predetermined content is sufficiently mixed by amixer or the like, and then the resultant is mixed or melted and kneadedby a mixing roll, an extruder, a kneader, or a planetary mixer,thereafter, the resultant is cooled, defoamed if necessary, and crushed,or the like can be exemplified. In addition, the epoxy resin compositionmay be formed into a tablet with a dimension and mass conforming to themolding condition if necessary.

As a method of sealing an electronic component device such as asemiconductor device using the epoxy resin composition of the presentinvention, a low pressure transfer molding method is the most general,but an injection molding method, a compression molding method, adispensing method, a casting method, a printing method, or the like maybe used.

<Electronic Component Device>

The electronic component device of the present invention is equippedwith an element sealed by the above described epoxy resin composition ofthe present invention. Examples of the electronic component deviceinclude an electronic component device, in which an active element suchas a semiconductor chip, a transistor, a diode, or a thyristor, and/or apassive element such as a capacitor, a resistor or a coil are mounted ona supporting member such as a lead frame, a pre-wired tape carrier, acircuit board, a glass, or a silicon wafer, and then these are sealed bythe epoxy resin composition of the present invention.

More specific examples of the electronic component device include ageneral resin sealing type IC such as a DIP (Dual Inline Package), aPLCC (Plastic Leaded Chip Carrier), a QFP (Quad Flat Package), a SOP(Small Outline Package), a SOJ (Small Outline J-lead package), a TSOP(Thin Small Outline Package), or a TQFP (Thin Quad Flat Package), whichis obtained by fixing a semiconductor element on a lead frame,connecting a terminal portion and a lead portion of the element such asa bonding pad to each other by wire bonding or a bump, and sealing theelement by transfer molding or the like using the epoxy resincomposition of the present invention; a TCP (Tape Carrier Package)obtained by sealing a semiconductor chip connected to a tape carrier bya bump using the epoxy resin composition of the present invention; a COB(Chip On Board) module, a hybrid IC, or a multichip module obtained bysealing an active element such as a semiconductor chip, a transistor, adiode, or a thyristor, and/or a passive element such as a capacitor, aresistor or a coil connected to wiring formed on a circuit board or aglass by wire bonding, flip chip bonding, or solder with the epoxy resincomposition of the present invention; and a BGA (Ball Grid Array) or aCSP (Chip Size Package) obtained by mounting an element on the frontsurface of an organic substrate having a terminal for circuit boardconnection formed on the rare surface, connecting the element and thewiring formed on the organic substrate to each other by a bump or wirebonding, and sealing the element with the epoxy resin composition of thepresent invention.

The epoxy resin composition of the present invention exhibits a highglass transition temperature in a case in which the epoxy resincomposition is formed into a cured product, and the decrease in elasticmodulus and mass at a high temperature is small in degree, and thus canbe suitably used in an application requiring heat resistance and hightemperature performance guarantee. Specific applications include asemiconductor package operating even at a high temperature, such as apower module package, an in-vehicle application package, SiC, and GaN.In addition, the epoxy resin composition of the present invention can beeffectively used for a printed circuit board as well.

The disclosure of Japanese Patent Application No. 2011-215338 isincorporated by reference herein in their entireties.

All the literature, patent applications, and technical standards citedherein are also herein incorporated to the same extent as provided forspecifically and severally with respect to an individual literature,patent application, and technical standard to the effect that the sameshould be so incorporated by reference.

EXAMPLES

Hereinafter, the present invention will be more specifically describedwith reference to Examples, but the scope of the present invention isnot limited to these Examples. Meanwhile, the term “%” means “% by mass”unless otherwise stated.

<Arrangement of Each Constituent of Epoxy Resin Composition>

(A) Epoxy Resin

-   -   Epoxy resin 1: trisphenolmethane type epoxy resin (the epoxy        resin of Formula (I), the content of the compound of Formula        (I-1) is 46%, n represents an integer from 0 to 10, epoxy        equivalent: 170, Trade name: 1032H60 manufactured by Mitsubishi        Chemical Corporation (formerly Japan Epoxy Resins Co., Ltd.))    -   Epoxy resin 2: naphthalenediol aralkyl type epoxy resin (epoxy        equivalent: 164, Trade name: ESN-355 manufactured by Nippon        Steel Chemical Co., Ltd. (formerly Toto Kasei, Co.))    -   Epoxy resin 3: o-cresol novolac type epoxy resin (epoxy        equivalent: 195, Trade name: ESCN-190-2 manufactured by Sumitomo        Chemical Co., Ltd.)    -   Epoxy resin 4: biphenyl type epoxy resin (epoxy equivalent: 196,        Trade name: YX-4000H manufactured by Mitsubishi Chemical        Corporation (formerly Japan Epoxy Resins Co., Ltd.))    -   Epoxy resin 5: biphenylene type epoxy resin (epoxy equivalent:        273, Trade name: NC-3000 manufactured by NIPPON KAYAKU Co.,        Ltd.)

(B) Phenol Resin

-   -   Phenol resin 1: the phenol resin of Formula (II), which contains        1,6-dihydroxynaphthalene at 30% (n represents an integer from 0        to 10, R¹ represents a hydrogen atom, hydroxyl group equivalent:        110, Trade name: SN-395 and lot number: 71101 manufactured by        Nippon Steel Chemical Co., Ltd. (formerly Toto Kasei, Co.))    -   Phenol resin 2: the phenol resin of Formula (II), which contains        1,6-dihydroxynaphthalene at 47% (n represents an integer from 0        to 10, R¹ represents a hydrogen atom, hydroxyl group equivalent:        100, Trade name: SN-375 and lot number: P-20033 manufactured by        Nippon Steel Chemical Co., Ltd. (formerly Toto Kasei, Co.))    -   Phenol resin 3: the phenol resin of Formula (II), which contains        1,6-dihydroxynaphthalene at 60% (n represents an integer from 0        to 10, R¹ represents a hydrogen atom, hydroxyl group equivalent:        99, Trade name: SN-375 and lot number: P-090810 manufactured by        Nippon Steel Chemical Co., Ltd. (formerly Toto Kasei, Co.))    -   Phenol resin 4: trisphenolmethane type phenol resin (hydroxyl        group equivalent: 103, Trade name: MEH-7500 manufactured by        MEIWA PLASTIC INDUSTRIES, LTD.)    -   Phenol resin 5: phenol novolac type phenol resin (hydroxyl group        equivalent: 106, Trade name: HP-850N manufactured by Hitachi        Chemical Co., Ltd.)    -   Phenol resin 6: biphenylenedimethylene type phenol resin        (hydroxyl group equivalent: 199, Trade name: HE-200C-10        manufactured by AIR WATER INC (formerly Air Water Chemical Co.,        Ltd.))

The content of 1,6-dihydroxynaphthalene contained in the phenol resin 1,the phenol resin 2, and the phenol resin 3 was measured using a gelpermeation chromatography (GPC). The conditions of the GPC were asfollows.

[Condition of GPC]

-   -   Pump: L6200 Pump (manufactured by Hitachi, Ltd.)    -   Detector: refractive index detector L3300 RI Monitor        (manufactured by Hitachi, Ltd.)    -   Column: TSK gel-G5000HXL and TSK gel-G2000HXL (total 2 columns)        (both of them are manufactured by TOSOH CORPORATION) are used by        connecting in series.    -   Eluent: tetrahydrofuran    -   Flow rate: 1 ml/min    -   Temperature of column oven: 30° C.

[Content of Dihydroxynaphthalene Compound]

GPC charts for the phenol resin 1, the phenol resin 2, and the phenolresin 3 are shown in FIGS. 1, 2, and 3. The peaks for1,6-dihydroxynaphthalene in FIGS. 1 to 3 are the peaks at about 20.5minutes, and the peaks at from 16 minutes to 20 minutes indicate themixture of 1,6-naphthalenediol aralkyl resin. The content of the (C)dihydroxynaphthalene compound was calculated from the percentage ofspectrum area obtained from this. The content (C)/[(B)+(C)] of theconstituent (C) with respect to the total amount of the constituent (B)and the constituent (C) was calculated by taking the constituent ofdihydroxynaphthalene compound in the phenol resin as (C) and theconstituents other than the constituent (C) as (B), and the content thusobtained was taken as the content of the dihydroxynaphthalene compound.

(D) Antioxidant

Hindered phenolic antioxidant (Trade name: AO-60 manufactured by ADEKACORPORATION)

(E) Curing Accelerator

Product of addition reaction of triphenylphosphine and 1,4-benzoquinone

(F) Inorganic Filler

Spherical fused silica having an average particle size (D50) of 17.5 μmand a specific surface area of 3.8 m²/g

(Other Additives)

Coupling agent: epoxysilane (γ-glycidoxypropyltrimethoxysilane)Colorant: carbon black (Trade name: MA-100 manufactured by MitsubishiChemical Corporation)

Mold releasing agent: carnauba wax (manufactured by CERARICA NODA Co.,Ltd.)

<Preparation of Epoxy Resin Composition>

Each of the constituents described above was blended at the part by massshown in the following Tables 1 and 2, and then roll kneading wasperformed under the condition of a kneading temperature of 80° C. and akneading time of 15 minutes, thereby obtaining each of the epoxy resincompositions of Examples 1 to 9 and Comparative Examples 1 to 8.

<Molding of Epoxy Resin Composition>

Next, each of the epoxy resin compositions obtained according toExamples 1 to 9 and Comparative Examples 1 to 8 was evaluated by each ofthe tests to be described below, and the results thereof are shown inTables 1 and 2.

Meanwhile, the molding of the epoxy resin composition was performedusing a transfer molding machine and under the condition of a moldtemperature of 180° C., a molding pressure of 6.9 MPa, and a heatingtime for curing of 90 seconds.

<Evaluation>

(Glass Transition Temperature)

The molding of the epoxy resin composition was performed using a mold,by which a specimen having a length of 80 mm, a width of 10 mm, and athickness of 3 mm is molded, under the above described moldingcondition, and after cure was further performed for 6 hours at 250° C.Subsequently, the specimen was cut into a piece having a length of 50 mmand a width of 5 mm using a diamond cutter, and then the measurement wasperformed using a viscoelasticity measuring apparatus RSA3 (manufacturedby TA Instruments.) at three-point bending mode, and under the conditionof a temperature rising speed of 5° C./min and a frequency of 6.28rad/s. The peak value for tan 6 was taken as the glass transitiontemperature. The measurement results of glass transition temperature areshown in Tables 1 and 2.

(Fluidity)

The molding of an epoxy resin composition for sealing was performed by atransfer molding machine using a mold for spiral flow measurement basedon EMMI-1-66 and under the condition of a mold temperature of 180° C., amolding pressure of 6.9 MPa, and a heating time for curing of 90seconds, and then the flow distance (cm) was obtained. The measurementresults of fluidity are shown in Tables 1 and 2.

(Elastic Modulus Retention)

A specimen same as the specimen for the measurement method of glasstransition temperature was prepared, and then the elastic modulusretention was measured with respect to this specimen using aviscoelasticity measuring apparatus RSA3 (manufactured by TAInstruments.) at three-point bending mode and under the condition of atemperature rising speed of 5° C./min and a frequency of 6.28 rad/s.Thereafter, the elastic modulus retention was calculated by thefollowing Mathematical Formula (1) from the elastic modulus (A¹) at 60°C. and the elastic modulus (B¹) at 250° C. The evaluation results ofelastic modulus retention are shown in Tables 1 and 2.

Elastic modulus retention (%)=B ¹ /A ¹×100  Mathematical Formula (1)

(Mass Retention)

The molding of an epoxy resin composition was performed using a mold, bywhich a circular plate having a diameter of 50 mm and a thickness of 3mm is molded, and under the above described molding condition, and thenafter cure was performed for 6 hours at 250° C. Thereafter, a mass (A²)of the resultant was measured. Next, the circular plate thus obtainedwas stored in a high temperature oven of 250° C. and taken out after apredetermined time (1008 h), and a mass (B²) thereof was measured. Themass retention was calculated by the following Mathematical Formula (2)by subtracting the mass of inorganic filler from the total mass of epoxyresin composition, and then converting into the resin content using themass (A²) and the mass (B²). The evaluation results of mass retentionare shown in Tables 1 and 2.

Mass retention (%)=(B ² mass of inorganic filler in epoxy resincomposition)/(A ² mass of inorganic filler in epoxy resincomposition)×100  Mathematical Formula (2)

TABLE 1 Examples Items 1 2 3 4 5 6 7 8 9 Epoxy 1 100 100 80 100 100 10080 100 100 Resin 2 3 20 20 4 5 Phenol 1 65 63 52 65 63 52 Resin 2 59 593 58 4 13 13 5 6 Antioxidant Part by mass 5 5 5 5 Curing Part by mass 22 2 2 2 2 2 2 2 Accelerator Coupling Part by mass 11 11 11 11 11 11 1111 11 Agent Mold Part by mass 1 1 1 1 1 1 1 1 1 Releasing Agent ColorantPart by mass 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 Inorganic Part by mass1023 990 1013 1018 1051 1018 1042 1046 986 Filler % by mass in 85 85 8585 85 85 85 85 85 Resin Composition Evaluation Glass Transition 286 254253 260 276 246 243 251 226 Items Temperature (° C.) Fluidity 78 105 9092 82 110 93 85 120 Elastic modulus 57 45 50 54 56 45 49 54 18 Retention(%) Weight Retention 88 88 87 88 95 93 92 92 88 (%)

TABLE 2 Comparative Examples Items 1 2 3 4 5 6 7 8 Epoxy 1 100 100 100Resin 2 100 100 3 100 4 100 5 100 Phenol 1 Resin 2 61 51 37 3 4 61 63 554 62 6 117 Antioxidant Part by mass Curing Part by mass 2 2 2 2 2 2 2 2Accelerator Coupling Part by mass 11 11 11 11 11 11 11 11 Agent MoldPart by mass 1 1 1 1 1 1 1 1 Releasing Agent Colorant Part by mass 2.62.6 2.6 2.6 2.6 2.6 2.6 2.6 Inorganic Part by mass 1000 1318 1012 1002964 1009 946 864 Filler % by mass in 85 85 85 85 85 85 85 85 ResinComposition Evaluation Glass Transition 209 160 208 229 168 183 124 132Items Temperature (° C.) Fluidity 115 138 107 54 116 107 168 165 ElasticModulus 16 8 15 19 12 11 8 8 Retention (%) Weight Retention 88 92 86 7872 85 93 93 (%)

As can be seen from Tables 1 and 2, Examples 1 to 9 using the epoxyresin composition of the present invention exhibit a high glasstransition temperature, and exhibit excellent reliability as massdecrease is small in degree (weight retention is high) even afterstoring under a high temperature environment of 250° C. when compared toComparative Examples 1 to 8. From the result above, it has been foundout that the combination of the trisphenolmethane type epoxy resin andthe naphthalenediol aralkyl resin prescribed in the present invention isimportant. In addition, it has been found out that the epoxy resincomposition of the present invention can provide a semiconductor devicesuitable for a use under a high temperature environment when formed as acured product.

Since a trisphenolmethane type phenol resin is used for ComparativeExample 3, The glass transition temperature thereof is not elevated evenwhen a naphthalenediol aralkyl type epoxy resin is used as an epoxyresin. The reason for this is considered as follows. Steric hindranceoccurs when a part of the trisphenolmethane type phenol resin reactswith the epoxy resin, and thus the reaction of an adjacent phenolichydroxyl group with the epoxy resin is inhibited. As a result, crosslinkdensity does not increase, and thus glass transition temperature is notelevated.

On the other hand, it has been found out that the Examples 5 to 8, inwhich an antioxidant is added, exhibit less decrease in weight afterstoring under a high temperature environment (250° C.). In addition, ithas been found out that the Examples 1 to 8, in which the phenol resins1 and 2 having the content of the dihydroxynaphthalene compound withrespect to the total amount of the naphthalenediol aralkyl resin and thedihydroxynaphthalene compound in the range of from 10% by mass to 55% bymass are used, exhibit superior glass transition temperature and elasticmodulus retention compared to Example 9, in which the phenol resin 3containing the dihydroxynaphthalene compound at more than 55% by mass isused.

1. An epoxy resin composition, comprising: (A) an epoxy resin includinga compound represented by the following Formula (I); (B) a phenol resinincluding a compound represented by the following Formula (II); and (C)a dihydroxynaphthalene compound including a compound represented by thefollowing Formula (III):

wherein, in Formula (I), R represents a hydrogen atom, and n representsan integer from 0 to 10;

wherein, in Formula (II), R¹ represents a hydrogen atom, an alkyl grouphaving from 1 to 6 carbon atoms, or an alkoxy group having 1 or 2 carbonatoms, and each R¹ may be the same as or different from another R¹; andn represents an integer from 0 to 10; and

wherein, in Formula (III), R¹ represents a hydrogen atom, an alkyl grouphaving from 1 to 6 carbon atoms, or an alkoxy group having 1 or 2 carbonatoms.
 2. The epoxy resin composition according to claim 1, wherein thecompound represented by Formula (II) includes a phenol resin representedby the following Formula (IV):

wherein, in Formula (IV), R¹ represents a hydrogen atom, and nrepresents an integer from 0 to
 10. 3. The epoxy resin compositionaccording to claim 1, wherein a content of a total amount of thecompound represented by Formula (III) with respect to a total amount ofthe compound represented by Formula (II) and the compound represented byFormula (III) is from 10% by mass to 55% by mass.
 4. The epoxy resincomposition according to claim 1, further comprising an antioxidant. 5.An electronic component device, comprising an element sealed by theepoxy resin composition according to claim 1.